With the release of Creative Suite 4, Adobe introduced a new model for Help content. Community Help provides user comments and expert moderation on the Help pages themselves, along with optimized web searches that focus on Adobe-approved content for each application.
For a visual explanation of all the options for browsing, searching, and filtering content, check out the following content:
Community Help video: http://tv.adobe.com/#vi+f1612v1009
Community Help instructions: http://help.adobe.com/en_US/CommunityHelp/